Multiple sclerosis (MS) is a chronic autoimmune inflammatory disease of the central nervous system. It is a common cause of persistent disability in young adults. In patients suffering from MS, the immune system destroys the myelin sheet of axons in the brain and the spinal chord, causing a variety of neurological pathologies. In the most common form of MS, Relapsing-Remitting, episodes of acute worsening of neurological function (exacerbations, attacks) are followed by partial or complete recovery periods (remissions) that are free of disease progression (stable). It has been reported that ninety percent of patients with MS initially present with a clinically isolated syndrome because of an inflammatory demyelinating lesion in the optic nerve, brain stem, or spinal cord. About thirty percent of those patients with a clinically isolated syndrome progress to clinically definite MS within 12 months after presentation. The subsequent progression of the disease can vary significantly from patient to patient. The progression can range from a benign course to a classic relapsing-remitting, chronic progressive, or rare fulminant course.
A method for diagnosing MS that facilitates early detection of clinically definite MS would be valuable for both managing the disease and providing counsel for the patient. For example, patients diagnosed early with clinically definite MS could be offered disease modifying treatments that have recently been shown to be beneficial in early MS.
Current methods for assessment and tracking progress of MS are based on assessment and scoring of patients' function in attacks and accumulated disabilities during the attacks. One assessment used to assess MS is the commonly used Expanded Disability Status Scale (EDSS). However, EDSS is based on a subjective assessment of patient function.
Methods for diagnosis can also include tracking brain lesions by Magnetic Resonance Imaging (MRI) or testing Cerebrospinal Fluid (CSF) for Oligo-Clonal Banding (OCB). MRI is a physical method for assessment of brain lesions and is expensive for routine use. Moreover, the correlation between MRI results and disease activity is poor. Cerebrospinal Puncture is an un pleasant invasive procedure that is not suitable for routine use. In addition, both methods assess damage only after it has occurred; neither method can predict the onset of attacks. A further disadvantage in testing for OCB in CSF and MRI as a way to diagnose MS is that a negative OCB or MRI will not preclude the existence of MS.
There is a need for a method that uses objectively assessed markers for diagnosing MS and for predicting the onset of attacks in patients suffering from MS.